These factors are included in a "Manual J" calculation. Contractors who make these calculations before recommending a size can take a couple of hours collecting the information and making the calculation. If your contractor doesn't do it, there are services that will do it for around $99. If you're feeling particularly on the ball, there are also free online calculators.
I recently replaced my 44 year old furnace. Over the years we have had several construction projects inside the home. For many years breathing the heated air from the duct work caused excessive sneezing, sinus issues, and lung irritation. . The heat smelled like dust. To maximize air quality I added a humidifier, MERV-11 filter, and UV light onto the new furnace. To further improve air quality, I had the ducts cleaned and sanitized. I took before and after pictures of the inside of each return and output duct. They were filthy before, and sparkling clean and fresh after the procedure. Now when running the system, clean sanitized air flows through my whole house. A huge difference. It will make sleeping and being indoors during the winter months far more tolerable. I use window air conditioners, and run the system in the summer to keep the house air clean and fresh on hot summer days too. It works! Great decision!

If not properly installed, maintained and operated, these components may become contaminated with particles of dust, pollen or other debris. If moisture is present, the potential for microbiological growth (e.g., mold) is increased and spores from such growth may be released into the home's living space. Some of these contaminants may cause allergic reactions or other symptoms in people if they are exposed to them. If you decide to have your heating and cooling system cleaned, it is important to make sure the service provider agrees to clean all components of the system and is qualified to do so. Failure to clean a component of a contaminated system can result in re-contamination of the entire system, thus negating any potential benefits. Methods of duct cleaning vary, although standards have been established by industry associations concerned with air duct cleaning. Typically, a service provider will use specialized tools to dislodge dirt and other debris in ducts, then vacuum them out with a high-powered vacuum cleaner.
Central, "all-air" air-conditioning systems (or package systems) with a combined outdoor condenser/evaporator unit are often installed in North American residences, offices, and public buildings, but are difficult to retrofit (install in a building that was not designed to receive it) because of the bulky air ducts required. (Minisplit ductless systems are used in these situations.) Outside of North America, packaged systems are only used in limited applications involving large indoor space such as stadiums, theatres or exhibition halls.
I agree, if you replace (or wash depending on type) your air filters regularly AND vaccum, then you probably don't need the ducts or air coils cleaned. However, if you purchase a pre-owned home, and the previous owners did not regularly change the air filter or vaccum the home, then duct cleaning is worth the expense especially if you are sensitive to allergens. Especially if the previous owners had pets.
I had someone out to clean my ducts last weekend. He took a blue bag up in my attic. He came back down in just a few minutes and said I had mold and he even showed me a picture of something saying it was mold but I couldn’t really tell. I refused his service to take care of the mold. He went back up in the attic for a little while and then came down. I never heard any sounds that he was actually up there doing anything. How do I know if he actually cleaned the air ducts?
Most organizations concerned with duct cleaning, including EPA, NADCA, NAIMA and the Sheet Metal and Air Conditioning Contractors' National Association (SMACNA) do not currently recommend the routine use of sealants to encapsulate contaminants in any type of duct. Instances when the use of sealants to encapsulate the duct surfaces may be appropriate include the repair of damaged fiber glass insulation or when combating fire damage within ducts. Sealants should never be used on wet duct liner, to cover actively growing mold, or to cover debris in the ducts, and should only be applied after cleaning according to NADCA or other appropriate guidelines or standards.
Asbestos removal tip.  Don’t trust any HVAC installation company that says that they will remove asbestos for you. They will do either one of two things: remove it and do a horrible job because they don’t know how (an illegal act in California, finable by up to $250,000), or they will say they did and never actually do it, which is dangerous to your health. Any HVAC contractor worth their weight will know not to touch it. Call an asbestos abatement company – it should cost around $500-$1,000, and your HVAC installation company will come in right after them and do the installation to decrease cost and inconvenience.
Some systems include an "economizer mode", which is sometimes called a "free-cooling mode". When economizing, the control system will open (fully or partially) the outside air damper and close (fully or partially) the return air damper. This will cause fresh, outside air to be supplied to the system. When the outside air is cooler than the demanded cool air, this will allow the demand to be met without using the mechanical supply of cooling (typically chilled water or a direct expansion "DX" unit), thus saving energy. The control system can compare the temperature of the outside air vs. return air, or it can compare the enthalpy of the air, as is frequently done in climates where humidity is more of an issue. In both cases, the outside air must be less energetic than the return air for the system to enter the economizer mode.
My vent covers have lots of mildew. They look bad! I live in a very humid climate in a condo. The handyman here has offered to take those down, wash them, sand, & then spray paint them with a mildew resistant paint. He said that he will leave them off overnight to dry. I am wondering if this is safe to breath the AC blowing out into the open all night??. ! Guess it is better than the mildew!?
I am in need of HVAC ADVICE!! I need a new furnace badly, mine is cracked. I have bought both a 95 % AFUE furnace and a 5 Ton evap coil, I figured it should all be replaced at once for both cost and efficency. My question is with all the negaitive things I have heard about companies ripping you off, what type of price should I pay someone for putting in those two items and bringing everything in my attic up to code? I have been quoted $550 - $ 3300. Wide margin here!! Then of course comes the licencing part!! I know in my heart that I should use a licenced contractor but I have had such bad luck and prices from them that honestly one that was licened in Ga. and just not here in TN and is a tech. which charges 1100 - 2200 less sounds good as so long as I pay some type of Profenial HVAC person say $100 to inspect the work after its done and before I pay them.
Although most new homes have ducts and vents already in place, many older homes have old convection heating systems or baseboard heaters without ductwork. In such cases, you will need to install ducts and vents to provide the air conditioning with a flow system. This would be the time to explore upgrading the existing heating system as well, as it will be much cheaper to do together.
Be careful of dishonest HVAC contractors. There’s no magical formula to see if an HVAC contractor is scamming you, unfortunately, but remember that they typically do this in one of two ways: first, they are charging grossly low prices (far below everyone else), or second, they aren’t including what everyone else is. In the first situation, they will charge you change fees, other hidden fees, or they stole the equipment and are passing themselves off as legitimate contractors (very common in California these days). In the second situation, they are charging you a very fair price, but aren’t including what the other contractors are (i.e. charging $10,500 for the installation which is fair, but not including the ductwork which is a scam unless there is some other, complex stuff going on there).

There are multiple reasons to replace your HVAC system. If you have built additions onto your house, you may find your old system no longer meets the requirements for the new dimensions. Perhaps a new technological breakthrough has provided features that will improve your comfort and air quality. Most often, however, you need to replace your system because it no longer works properly.


When water damage strikes, you need to act quickly. Time is of the essence. We're available 24/7 to dispatch trained, certified crews, equipment and inspection tools specializing in water damage. With our national footprint and large coverage areas throughout the country we will arrive on site and begin work quickly, minimizing the damage to your home. 

But Tim, doesn’t this mean that a less-than-honest air conditioning company can just charge what he wants and say that it’s a difficult job? No. You see, dishonest contractors, typically, aren’t the brightest people (I figure if you’re still reading this, you’re warming up to me so I’m taking off the training-wheels). They aren’t smart enough to take difficulty into account, and will probably get confused if you ask them about it. They will tell you things like, “that’s how much the unit costs,” or “California has a new law that magically adds $5,000 to the price.”  Trust me, follow your gut, and you’ll be able to tell who the honest contractors are...or just use one of our ASM-approved contractors.
Had our ducts cleaned late April, 2016. Sodium Chlorite was sprayed into ducts after cleaning. Ever since, we have been bothered with eye and nasal passage irritation because of a “chemical” and “musty” odor. This odor is present whether or not a/c is on.) We are told the sodium chlorite (“EnviroCon, manufactured by Bio-Cide International) is used in hospital and nursing home settings and is not hazardous to health. The air duct company’s suggestion is that they come out and spray even more sodium chlorite…we absolutely don’t want this done! Have had various other recommendations about what we need to have done to remedy our problem. We will be unable to stay in our home if a resolution cannot be found. We’d be willing to replace the ductwork if necessary. (One professional suggested that the cleaning may have “knocked something loose” inside the ductwork and that is the source of the irritant.) This home was built in 1920…no idea when the present ductwork was installed. Any suggestions would be appreciated.
I took off stars for two reasons. Minus one star for issues trying to use the $50 for $25 voucher I purchased through Yelp. Although there was no minimum stipulated, the office wouldn't take it for the initial $59 diagnostic fee. If I used the 10% off First service that they offer, then they won't let me use the voucher on the actual repair bill.  I was stuck with paying the full $59 diagnostic fee.

Installing a split system may involve making modifications to the house itself for the necessary lines to be run. The heat exchangers are also more prone to picking up debris and must be cleaned on a regular basis. While they come with protective screens over the fan, care must still be taken to ensure that nothing gets in, especially in a home with children.
Wiring up the thermostat is usually pretty straightforward if an old one is being replaced. If a thermostat is being put in where one had never been before, that could involve running new wiring. The placement of the thermostat is also important so that its sensors can get an accurate reading of the temperature. A thermostat that is blocked by a bookcase or other large furniture will not get a good reading and will not perform efficiently.

Roof-mounted systems have the heating and cooling systems in one cabinet. Sometimes called "gas packs" (if the heater uses natural gas), they typically cost less than a comparable split system. In dry regions, most homes originally had "swamp-coolers" installed. When replacing them with HVAC systems, it's often cheaper to use existing mounts and ducting.
My mom just received service from this company. She paid $609 to have her frion replaced. After two uses the AC stops working. A young rep comes out to the house again and notifies her that her entire AC unit and furnace need to be replace for just shy of ten grand, though when her frion was refilled she was told that her system should last another five years. When they came back to tell her how her entire system needed to be replaced, they were generous enough to offer her a $300 credit on the nearly $10,000 estimate of replacing the entire system that was working fine until they touched it. My best assumption would be that there is a mishap with the system is due to their negligence. Id suggest using another company other than these scam artists.

As a homeowner and an owner of rental property I can tell you that the air ducts sometimes need to be cleaned. If you have had pets or anyone smoking in your home (even a visitor) for any length of time, having the ducts cleaned is really good idea. I had a tenant who did not smoke, but got married to a smoker more than year after moving in. When I realized someone was smoking I had them move out, but the smell was awful. I had the ducts cleaned and sanitized (it was a bit extra). The ducts were shiny like new afterwards. I left the windows open for a few days and we cleaned the place super clean and then replaced the carpets. The duct cleaning was worth every penny because the house looked, smelled, and felt new afterward. I plan to have my own house ducts cleaned again this year as we have two cats. We had them cleaned about 12 years ago and they found building materials in the ducts! If you move into a house that has never had them cleaned, it is good to do it. If you have allergies, clean the ducts to see if it helps. You never know what is in your ducts if you have never had them cleaned.

Fresh-Aire UV is an innovation leader in the field of indoor air quality. Our award-winning UV light and carbon products fight mold, bacteria, viruses and odors in commercial and residential HVACR systems. Our products include Blue-Tube UV®, the worlds most popular germicidal UV light, the revolutionary APCO® PCO/carbon whole-house air purifier, and Mini UV the first UV light system designed specifically for mini-split AC systems.


#3 The ONLY time Duct cleaning is needed is when the home had a fire, Bad roof leak on to FIBERGLASS ductwork or house sat vacant for many years with out the air running. And its better to replace than to do “abrasive” duct cleaning. If the duct cleaning has a rotating brush it will remove part of the glue that is holding the Fiberglass in the ducts together, PERIOD no matter how much the say it don’t because the brush is soft.

I turned on the AC when he was finished and immediately saw black fuzz balls the size of marbles come out of several of the registers. He said that was expected since everything was shaken up. So much for describing the service as cleaning. I paid him and sent him on his way. I cannot imagine that this type of service is worthwhile in anything but a new house. Apparently in old houses such as mine I can expect that using a whole house humidifier in the winter followed by a great AC can loosen the soot. Maybe this is to be expected for the first few weeks of summer each year. I now have lined the inside of the registers with cheesecloth to catch the fuzz. I’ll see if it stops after a couple of weeks.
As I type this, I am having my ducts cleaned. About 30 including returns and the furnace. $543.00. I am watching the team do it and can see the clear vacuuming tubing and how dirty it has become. I like the gentleman’s comment on “stick your head in your vacuum and breath”….I get it. The team showed me the machine and it’s filtration system…and they will show me it again after the cleaning. However, like I said before, I am actively seeing the tubing that is clear before they start and how dirty it is once they begin and continue cleaning. Reputable company and not a “fly by night” coupon service. People don’t be so cheap, that is your problem.

I always get a laugh at anyone claiming to be in the business for any length of time that doesnt understand the importance of cleaning out a ventilation system. Not only for better indoor air quality but for maintaining your heating equipment. I guess it makes more sense to some people that the furnace will just run better with a ton of dust and debris and maybe this wont be a big cause of sytem breakdown and malfunction. I mean really? Maybe this guy got a bad company and or cleaning and is a little jaded but to advise cleaning your grills , which does nothing, and replacing a filter....come on guy.
A little simple math can help determine the size system you need. A rule of thumb is 20 BTUs per square foot. So, a 500 square foot room would need 10,000 BTUs to cool or warm it efficiently. This assumes that you live in a temperate region and have adequate insulation with no energy loss. In the real world, all units have some degree of energy loss. This is reflected in an HVAC system's SEER rating for cooling and AFUE rating for heating.
HVAC System Quality Installation Contractor Checklist -- This checklist identifies all of the steps the contractor has taken for the Energy Star Certification and identifies what work the contractor has done. If the system is later modified, this checklist can help identify what was done to proper Energy Star specifications and what was added later that may not meet the requirements.
An important component of natural ventilation is air change rate or air changes per hour: the hourly rate of ventilation divided by the volume of the space. For example, six air changes per hour means an amount of new air, equal to the volume of the space, is added every ten minutes. For human comfort, a minimum of four air changes per hour is typical, though warehouses might have only two. Too high of an air change rate may be uncomfortable, akin to a wind tunnel which have thousands of changes per hour. The highest air change rates are for crowded spaces, bars, night clubs, commercial kitchens at around 30 to 50 air changes per hour.[17]
We were following up on this review and the service call we did for you. We could not find you in our system of ever having gone out to your home. If you could please provide us with the date we were out and the name under which the call was placed that would be great as we would like to see if there is any way we can rectify the situation. We do offer a 100% Satisfaction Guarantee, we have tried to private message you to no avail. Can you please call us at 925-318-4795?  
Hi guys if your not convinced yet that duct cleaning is a waste of time. I’m a HVAC business owner install heaters and air conditioners. Simple facts if you have an old system get a new return air fitted with a filter it will catch all the dirt and dust. If you still have as many do black flecks and stuff coming through it is the lining inside your ducting that has perished. So somewhere you have a hole or very old ducting. If you had rats etc its a hole somewhere. To clean, stick your vacuum in the outlet and push the hose as far as it will go this gets 99% of toys and coins fur and alike. Think about it if the object is not heavy it will come out the duct when unit is on. Service the heaters or air con units but not the ducting. I would go further to say that duct cleaning actually damages the ducting in my opinion.
I took off stars for two reasons. Minus one star for issues trying to use the $50 for $25 voucher I purchased through Yelp. Although there was no minimum stipulated, the office wouldn't take it for the initial $59 diagnostic fee. If I used the 10% off First service that they offer, then they won't let me use the voucher on the actual repair bill.  I was stuck with paying the full $59 diagnostic fee.
What you might not know is that the brand you choose is one of the most important factors in determining a fair HVAC installation cost. So, before delving in-depth, let’s take a quick look at the average prices of a new air conditioner and matching coil by brand…keep in mind, these are the average prices (by brand) that contractors pay for your AC equipment, and it is meant to give you a rough guideline until you are closer to buying:
One problem occurred on Monday.  When we called at 2:30 in the afternoon to check on status, we were told that "the tech is on the phone with the parts supplier now".  It seems more likely that they had forgotten about us and our call woke them up.  But even if true, why the heck did they wait until 2:30 to order the part?  Maybe if they had ordered it in the morning they could have had it the same day.  So I'm taking off one star for that.
The heat pump gained popularity in the 1950s in Japan and the United States.[13] Heat pumps can extract heat from various sources, such as environmental air, exhaust air from a building, or from the ground. Heat pumps transfer heat from outside the structure into the air inside. Initially, heat pump HVAC systems were only used in moderate climates, but with improvements in low temperature operation and reduced loads due to more efficient homes, they are increasing in popularity in cooler climates.

In addition, the service provider may propose applying chemical biocides, designed to kill microbiological contaminants, to the inside of the duct work and to other system components. Some service providers may also suggest applying chemical treatments (sealants or other encapsulants) to encapsulate or cover the inside surfaces of the air ducts and equipment housings because they believe it will control mold growth or prevent the release of dirt particles or fibers from ducts. These practices have yet to be fully researched and you should be fully informed before deciding to permit the use of biocides or chemical treatments in your air ducts. They should only be applied, if at all, after the system has been properly cleaned of all visible dust or debris.

×